Common questions,
straight answers.

Occasional pressure drops (once or twice a year) are normal. If you're repressurising monthly or more, there is a leak in the system. Check all radiator valves and pipe joints for damp patches or white mineral deposits. A failing expansion vessel is another common cause — it causes pressure to spike when hot and drop when cold.

Find the filling loop — usually a braided silver hose with two small valves, located under or near the boiler. Turn both valves to the open position (slot in line with the pipe). Watch the pressure gauge rise. When it reaches 1–1.5 bar, close both valves. Press the boiler reset button. Do this with the boiler cold for best accuracy.

Fault codes are your boiler's way of telling you why it has locked out. Some codes (typically low pressure codes like F22 on Vaillant, E10 on Baxi) are safe to remedy yourself and reset once. Others — fan faults, gas valve faults, overheat lockouts — should not be repeatedly reset. Never reset a boiler more than twice for the same fault.

Trapped air is the answer — almost every time. Air rises in the system and collects at the top of the radiator. The fix takes about 10 minutes: use a radiator bleed key to open the bleed valve at the top corner until water flows out (no more hissing). Afterwards, check your boiler pressure and repressurise if it has dropped.

Remove the cistern lid and watch what's happening. If water is trickling into the pan: press the rubber flap valve at the bottom — if it stops, the flap valve is worn (a £3–£8 part). If water is running into the overflow pipe outside: the fill valve isn't shutting off — try bending the float arm downward slightly.

A dripping tap is almost always a worn washer or cartridge. For traditional pillar taps: it's a rubber washer, which costs pennies. For quarter-turn ceramic taps: the ceramic cartridge has cracked. For single-lever mixer taps: the internal cartridge is worn. All are DIY-friendly if you're comfortable turning off the water supply.

When the system is cold (before the heating has been on), pressure should read between 1 and 1.5 bar. When the heating is running and the system is warm, pressure naturally rises to 1.5–2 bar — this is completely normal. Below 0.5 bar: the boiler may not fire. Above 3 bar: call a Gas Safe engineer.

Act immediately: Do NOT turn any electrical switches on or off. Do NOT use a naked flame. Open windows and doors. Leave the property. Call the National Gas Emergency Service from outside: 0800 111 999 (free, 24/7). Do not return until told it is safe.

Safe DIY: replacing tap washers, bleeding radiators, repressurising the boiler, fixing a running toilet, unblocking a sink. Always use a Gas Safe registered engineer for any gas work — it is illegal to carry out gas work without registration. Unvented cylinder work also requires specialist certification.

Most boilers last 10–15 years with regular servicing. After that, repair costs often outweigh replacement costs — and a new A-rated boiler will be significantly cheaper to run.

Every year, ideally before winter. An annual service keeps your warranty valid, catches small problems early, and is a legal requirement for landlords (CP12 certificate).

A combi (combination) boiler heats water on demand from the mains — no cylinder or loft tank needed. It provides both central heating and instant hot water from one compact unit, and is the most popular boiler type in UK homes.

Yes — set it to hot water only and switch off the heating entirely. Running the heating briefly once a month in summer keeps the pump from seizing, which is worth doing on older systems.

Short cycling is usually caused by low water pressure, a faulty thermostat, a blocked condensate pipe, or an oversized boiler. Check the pressure gauge first — it should read 1–1.5 bar when cold.

The condensate pipe carries acidic wastewater from your condensing boiler to an outside drain. In cold weather it freezes, causing the boiler to lock out. Pour warm (not boiling) water over the outside section to thaw it.

Yes. A yellow or orange flame can indicate incomplete combustion and a carbon monoxide risk. Turn the boiler off, ventilate the room, and call a Gas Safe registered engineer before using it again.

1–1.5 bar when the system is cold — the needle should sit in the green zone on the pressure gauge. Below 0.5 bar the boiler locks out; above 3 bar the pressure relief valve discharges. Pressure that keeps dropping indicates a leak somewhere.

A standard annual boiler service costs £60–£120 depending on the engineer and your location. London and the South East are at the higher end. Always use a Gas Safe registered engineer.

Supply and installation typically costs £1,500–£3,000. A mid-range Worcester Bosch or Vaillant fully installed is usually £2,000–£2,500. Prices are higher in London. Always get at least three quotes.

It makes most sense if your boiler is over 7 years old, if an unexpected £500+ repair would be difficult, or if you're a landlord. For newer boilers under manufacturer warranty, check your home insurance first — it may already cover breakdowns.

Usually a balancing problem. Radiators closest to the boiler get more heat; those furthest away get less. Balancing the system by adjusting lockshield valves distributes heat more evenly. Also check TRVs are not set too low in cold rooms.

A Thermostatic Radiator Valve controls flow based on room temperature — the numbered dial lets you set the target temperature for that room. Setting 3 is roughly 20°C. Do not fit a TRV in the same room as your main thermostat.

For most UK homes, a timer that heats before you need it and lets it cool when empty is more efficient than constant low heat. Smart thermostats make this easy to optimise for your routine.

Power flushing clears sludge and rust from your heating system. Signs you need it: radiators cold at the bottom, brown water when bleeding, noisy boiler, or a new boiler being fitted to an old system. Costs £400–£800 depending on the number of radiators.

A like-for-like radiator swap costs £150–£350 including supply and labour. Adding a radiator to a new location costs £300–£600 due to extra pipework. Make sure the radiator is correctly sized for the room — use our free BTU calculator.

In most UK homes it's under the kitchen sink. If not there, check under the stairs, in a hall cupboard, or near the front door. Turn it clockwise to close. The stop valve next to your water meter (usually outside near the boundary) is a backup.

Yes — a dripping tap wastes around 5,500 litres per year and adds to your water bill if you're metered. A washer costs pennies; a ceramic cartridge £5–£20. It's also one of the easiest DIY plumbing jobs to do yourself.

Turn off the main stopcock immediately. Turn off the boiler and immersion heater. Open all cold taps to drain the system. If water is near electrics, turn off the consumer unit. Then locate and repair the burst — or call a plumber if it's not accessible.

Most likely a leak from a bathroom or pipe in the floor above. Turn off water to that area and find the source — check toilet cisterns, bath/shower seals, radiator valves and pipework. If you can't identify it quickly, turn off the main stopcock. Water in ceilings can weaken plaster and cause electrical hazards.

A plumber typically charges £60–£120 including parts. Traditional taps need a new washer (pennies); ceramic disc taps need a cartridge (£5–£20). It's one of the easiest DIY jobs if you're comfortable with basic plumbing.

Most plumbers charge £40–£80 per hour, with London and the South East at £80–£120+/hr. Most jobs are quoted as a fixed price. A call-out fee of £50–£100 is common for emergency work. Always confirm whether VAT is included.

Brown or orange water usually means disturbed rust in the pipes — run the cold kitchen tap for a few minutes and it should clear. If it persists or has an odd smell, contact your water supplier. Brown hot water specifically often indicates a corroding cylinder.

Water hammer is a banging noise when you turn a tap off — caused by the pressure wave of rapidly stopped water. Fix with a water hammer arrestor, by securing loose pipes, or by fitting a pressure reducing valve if mains pressure is very high (over 4 bar).

Some rise when heating is on is normal (water expands when hot). If it rises above 3 bar, the pressure relief valve discharges. Persistent high pressure usually means the expansion vessel has failed — this needs an engineer to diagnose and fix.

Find the filling loop — usually a silver or braided hose under the boiler connecting mains supply to the heating circuit. Open both valves slowly until the pressure reads 1.0–1.5 bar, then close both. If pressure drops again within days, there is likely a leak in the system.

Homeowners can replace taps, toilets, showers, radiators and fix leaks. You cannot work on gas appliances or pipework — that requires a Gas Safe registered engineer. Unvented cylinders require a G3-qualified installer. Electric showers fall under Part P electrical regulations.

Most routine plumbing doesn't need building regs approval. Exceptions: installing an unvented hot water cylinder (G3 notification required), boiler replacement (installer self-certifies via Gas Safe), and some electrical work. A full bathroom refit generally doesn't need approval unless structural work is involved.

PTFE tape goes on male threaded connections (shower heads, tap tails, radiator connections) — wrap it clockwise 3–4 times. Do not use it on compression fittings (the olive seals those) or push-fit fittings. For larger threads like radiator valves, use hemp and jointing compound.

Two adjustable spanners, pipe cutter, PTFE tape, silicone sealant, push-fit and compression fittings, a basin wrench for under-sink taps, and a toilet fitting tool. A pipe freezing kit is useful if you need to work on a section without draining the whole system.

Do not operate any electrical switches. Open windows and doors. Get everyone out immediately. Call 0800 111 999 (National Gas Emergency, free 24/7) from outside. Do not re-enter until an engineer gives the all-clear. Even a faint smell of gas is an emergency.

Headache, dizziness, nausea, shortness of breath, and confusion — often worse at home and better when you leave. CO is colourless and odourless. If you suspect it: get fresh air, call 999, and don't go back inside. Fit a BS EN 50291 CO alarm near every gas appliance.

Check: 1) Is there a fault code? Reset once. 2) Is pressure 1–1.5 bar? If not, repressurise. 3) Is the thermostat set above room temperature? 4) Has the condensate pipe frozen? 5) Is the pilot light on (older boilers)? If none of these fix it, call an engineer — no heating in winter is urgent.

An electric shower heats cold mains water instantly using an element — it works even if the boiler is off. A mixer shower blends hot water from the boiler with cold mains — it depends on the boiler working. A thermostatic mixer maintains constant temperature regardless of pressure changes.

A new electric shower installed costs £300–£600. A thermostatic mixer shower with enclosure costs £500–£1,500+. A wet room costs £2,000–£5,000+. Costs rise if significant pipework or tiling is needed.